Coronary heart disease, which can manifest as heart attacks or sudden death from lethal arrhythmias, is the number one killer in the U.S. and worldwide. Accurate estimation of cardiovascular disease risk is a critical first step in applying life-saving preventative therapies to high risk populations. State-of-the-art methods to ascertain risk, however, remain imperfect. Evidence shows that measuring Cholesterol efflux capacity of a certain human serum fraction significantly enhances prediction accuracy of cardiovascular risk. Measurement of an aspect of Reverse Cholesterol Transport (RCT) with an assay that involves cultured cells and human serum samples improves the accuracy of clinical risk assessment for heart disease (Khera et al. (2011) N. Engl. J. Med. 364:127). However, because this assay entails tissue culture techniques, radiolabeled cholesterol, and a 72-hour turnaround time, its clinical utility is limited.